•  250
    Share the Sugar
    with Harvey Lederman and Dean Spears
    We provide a general argument against value incomparability, based on a new style of impossibility result. In particular, we show that, against plausible background assumptions, value incomparability creates an incompatibility between two very plausible principles for ranking lotteries: a weak "negative dominance" principle (to the effect that Lottery 1 can be better than Lottery 2 only if some possible outcome of Lottery 1 is better than some possible outcome of Lottery 2) and a weak form of ex…Read more
  •  143
    Should you be willing to forego any sure good for a tiny probability of a vastly greater good? Fanatics say you should, anti-fanatics say you should not. Anti-fanaticism has great intuitive appeal. But, I argue, these intuitions are untenable, because satisfying them in their full generality is incompatible with three very plausible principles: acyclicity, a minimal dominance principle, and the principle that any outcome can be made better or worse. This argument against anti-fanaticism can be t…Read more
  •  196
    Egyptians, Aliens, and Okies: Against the Sum of Averages
    with Michael Geruso and Dean Spears
    Utilitas 1-7. forthcoming.
    Grill (2023) defends the Sum of Averages View (SAV), on which the value of a population is found by summing the average lifetime welfare of each generation or birth cohort. A major advantage of SAV, according to Grill, is that it escapes the Egyptology objection to average utilitarianism. But, we argue, SAV escapes only the most literal understanding of this objection, since it still allows the value of adding a life to depend on facts about other, intuitively irrelevant lives. Moreover, SAV has…Read more
  •  375
    The epistemic challenge to longtermism
    Synthese 201 (6): 1-37. 2023.
    Longtermists claim that what we ought to do is mainly determined by how our actions might affect the very long-run future. A natural objection to longtermism is that these effects may be nearly impossible to predict — perhaps so close to impossible that, despite the astronomical importance of the far future, the expected value of our present actions is mainly determined by near-term considerations. This paper aims to precisify and evaluate one version of this epistemic objection to longtermism. …Read more
  •  78
    Longtermism in an infinite world
    In Jacob Barrett, Hilary Greaves & David Thorstad (eds.), Essays on Longtermism, Oxford University Press. forthcoming.
    The case for longtermism depends on the vast potential scale of the future. But that same vastness also threatens to undermine the case for longtermism: If the universe as a whole, or the future in particular, contain infinite quantities of value and/or disvalue, then many of the theories of value that support longtermism (e.g., risk-neutral total utilitarianism) seem to imply that none of our available options are better than any other. If so, then even apparently vast effects on the far future…Read more
  •  205
    All else being equal, most of us typically prefer to have positive experiences in the future rather than the past and negative experiences in the past rather than the future. Recent empirical evidence tends not only to support the idea that people have these preferences, but further, that people tend to prefer more painful experiences in their past rather than fewer in their future (and mutatis mutandis for pleasant experiences). Are such preferences rationally permissible, or are they, as time-…Read more
  •  306
    People are ‘biased toward the future’: all else being equal, we typically prefer to have positive experiences in the future, and negative experiences in the past. Several explanations have been suggested for this pattern of preferences. Adjudicating among these explanations can, among other things, shed light on the rationality of future-bias: For instance, if our preferences are explained by unjustified beliefs or an illusory phenomenology, we might conclude that they are irrational. This paper…Read more
  •  508
    Empirical work has lately confirmed what many philosophers have taken to be true: people are ‘biased toward the future’. All else being equal, we usually prefer to have positive experiences in the future, and negative experiences in the past. According to one hypothesis, the temporal metaphysics hypothesis, future-bias is explained either by our beliefs about temporal metaphysics—the temporal belief hypothesis—or alternatively by our temporal phenomenology—the temporal phenomenology hypothesis. …Read more
  •  1075
    What Should We Agree on about the Repugnant Conclusion?
    with Stephane Zuber, Nikhil Venkatesh, Torbjörn Tännsjö, H. Orri Stefánsson, Katie Steele, Dean Spears, Jeff Sebo, Marcus Pivato, Toby Ord, Yew-Kwang Ng, Michal Masny, William MacAskill, Nicholas Lawson, Kevin Kuruc, Michelle Hutchinson, Johan E. Gustafsson, Hilary Greaves, Lisa Forsberg, Marc Fleurbaey, Diane Coffey, Susumu Cato, Clinton Castro, Tim Campbell, Mark Budolfson, John Broome, Alexander Berger, Nick Beckstead, and Geir B. Asheim
    Utilitas 33 (4): 379-383. 2021.
    The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that the Repugnant Conclusion now receives too much focus. Avoiding the Repugnant Conclusion should no longer be the central goal driving population ethics research, despite its importance to the fundamental accomplishments of the existing literature.
  •  290
    Is the overall value of a world just the sum of values contributed by each value-bearing entity in that world? Additively separable axiologies (like total utilitarianism, prioritarianism, and critical level views) say 'yes', but non-additive axiologies (like average utilitarianism, rank-discounted utilitarianism, and variable value views) say 'no'. This distinction is practically important: additive axiologies support 'arguments from astronomical scale' which suggest (among other things) that it…Read more
  •  542
    Philosophers have long noted, and empirical psychology has lately confirmed, that most people are “biased toward the future”: we prefer to have positive experiences in the future, and negative experiences in the past. At least two explanations have been offered for this bias: belief in temporal passage and the practical irrelevance of the past resulting from our inability to influence past events. We set out to test the latter explanation. In a large survey, we find that participants exhibit sig…Read more
  •  719
    Decision-making under normative uncertainty requires an agent to aggregate the assessments of options given by rival normative theories into a single assessment that tells her what to do in light of her uncertainty. But what if the assessments of rival theories differ not just in their content but in their structure -- e.g., some are merely ordinal while others are cardinal? This paper describes and evaluates three general approaches to this "problem of structural diversity": structural enrichme…Read more
  •  109
    Normative Externalism, by Brian Weatherson (review)
    Mind 130 (519): 1018-1028. 2021.
    Rohana faces a choice where she can produce either a better outcome by lying or a worse outcome by telling the truth. She justifiably, but falsely, believes in
  •  56
    Rejecting Supererogationism
    Pacific Philosophical Quarterly 100 (2): 599-623. 2018.
    Even if I think it very likely that some morally good act is supererogatory rather than obligatory, I may nonetheless be rationally required to perform that act. This claim follows from an apparently straightforward dominance argument, which parallels Jacob Ross's argument for 'rejecting' moral nihilism. These arguments face analogous pairs of objections that illustrate general challenges for dominance reasoning under normative uncertainty, but (I argue) these objections can be largely overcome.…Read more
  •  1373
    Average Utilitarianism Implies Solipsistic Egoism
    Australasian Journal of Philosophy 101 (1): 140-151. 2023.
    ABSTRACT Average utilitarianism and several related axiologies, when paired with the standard expectational theory of decision-making under risk and with reasonable empirical credences, can find their practical prescriptions overwhelmingly determined by the minuscule probability that the agent assigns to solipsism—that is, to the hypothesis that there is only one welfare subject in the world, namely, herself. This either (i) constitutes a reductio of these axiologies, (ii) suggests that they req…Read more
  •  1054
    Longtermists claim that what we ought to do is mainly determined by how our actions might affect the very long-run future. A natural objection to longtermism is that these effects may be nearly impossible to predict -- perhaps so close to impossible that, despite the astronomical importance of the far future, the expected value of our present actions is mainly determined by near-term considerations. This paper aims to precisify and evaluate one version of this epistemic objection to longtermism.…Read more
  •  660
    How should you decide what to do when you're uncertain about basic normative principles (e.g., Kantianism vs. utilitarianism)? A natural suggestion is to follow some "second-order" norm: e.g., "comply with the first-order norm you regard as most probable" or "maximize expected choiceworthiness". But what if you're uncertain about second-order norms too -- must you then invoke some third-order norm? If so, it seems that any norm-guided response to normative uncertainty is doomed to a vicious regr…Read more
  •  122
    Normative Uncertainty and Social Choice
    Mind 128 (512): 1285-1308. 2019.
    In ‘Normative Uncertainty as a Voting Problem’, William MacAskill argues that positive credence in ordinal-structured or intertheoretically incomparable normative theories does not prevent an agent from rationally accounting for her normative uncertainties in practical deliberation. Rather, such an agent can aggregate the theories in which she has positive credence by methods borrowed from voting theory—specifically, MacAskill suggests, by a kind of weighted Borda count. The appeal to voting met…Read more
  •  2653
    The principle that rational agents should maximize expected utility or choiceworthiness is intuitively plausible in many ordinary cases of decision-making under uncertainty. But it is less plausible in cases of extreme, low-probability risk (like Pascal's Mugging), and intolerably paradoxical in cases like the St. Petersburg and Pasadena games. In this paper I show that, under certain conditions, stochastic dominance reasoning can capture most of the plausible implications of expectational reaso…Read more
  •  408
    Intertheoretic Value Comparison: A Modest Proposal
    Journal of Moral Philosophy 15 (3): 324-344. 2018.
    In the growing literature on decision-making under moral uncertainty, a number of skeptics have argued that there is an insuperable barrier to rational "hedging" for the risk of moral error, namely the apparent incomparability of moral reasons given by rival theories like Kantianism and utilitarianism. Various general theories of intertheoretic value comparison have been proposed to meet this objection, but each suffers from apparently fatal flaws. In this paper, I propose a more modest approach…Read more
  •  878
    Moral Uncertainty for Deontologists
    Ethical Theory and Moral Practice 21 (3): 505-520. 2018.
    Defenders of deontological constraints in normative ethics face a challenge: how should an agent decide what to do when she is uncertain whether some course of action would violate a constraint? The most common response to this challenge has been to defend a threshold principle on which it is subjectively permissible to act iff the agent's credence that her action would be constraint-violating is below some threshold t. But the threshold approach seems arbitrary and unmotivated: what would possi…Read more
  •  810
    Rationality and Moral Risk: A Moderate Defense of Hedging
    Dissertation, University of Maryland. 2017.
    How should an agent decide what to do when she is uncertain not just about morally relevant empirical matters, like the consequences of some course of action, but about the basic principles of morality itself? This question has only recently been taken up in a systematic way by philosophers. Advocates of moral hedging claim that an agent should weigh the reasons put forward by each moral theory in which she has positive credence, considering both the likelihood that that theory is true and the s…Read more
  •  91
    I describe a thought experiment in which an agent must choose between suffering a greater pain in the past or a lesser pain in the future. This case demonstrates that the ‘temporal value asymmetry’ – our disposition to attribute greater significance to future pleasures and pains than to past – can have consequences for the rationality of actions as well as attitudes. This fact, I argue, blocks attempts to vindicate the temporal value asymmetry as a useful heuristic tied to the asymmetry of causa…Read more
  •  92
    Does a discount rate measure the costs of climate change?
    Economics and Philosophy 33 (3): 337-365. 2017.
    I argue that the use of a social discount rate to assess the consequences of climate policy is unhelpful and misleading. I consider two lines of justification for discounting: (i) ethical arguments for a "pure rate of time preference" and (ii) economic arguments that take time as a proxy for economic growth and the diminishing marginal utility of consumption. In both cases I conclude that, given the long time horizons, distinctive uncertainties, and particular costs and benefits at stake in the …Read more